The present invention relates to a device and method that aids in the rehabilitation and restoration of muscular function in patients with impaired muscular function or control. More particularly, the present invention relates to a device and method suitable for therapeutic use with patients that have impaired neuromuscular/muscular function of the appendages, comprising a motorized system of braces and related control systems that potentiate improved function of the appendages for activities including, but not limited to, walking.
Millions of individuals suffer from either partial or total loss of walking ability. This disabled state can result from traumatic injury, stroke, or other medical conditions that cause disorders that affect muscular control. Regardless of origin, the onset and continuance of walking impairment can result in additional negative physical and/or psychological outcomes for the afflicted individual. In order to improve the health and quality of life of patients with walking impairment, the development of devices that can improve or restore walking function is of significant utility to the medical and therapeutic communities. Beyond walking impairment, there are a range of medical conditions that interfere with muscular control of the appendages, resulting in loss of function and other adverse conditions for the affected individual. The development of devices to improve or restore these functions is also of great interest to the medical and therapeutic communities.
Human exoskeleton devices are being developed in the medical field to restore and rehabilitate proper muscle function for people with disorders that affect muscle control. These exoskeleton devices are a system of motorized braces that can apply forces to the wearer's appendages. In a rehabilitation setting, exoskeletons are typically controlled by a physical therapist who uses one of a plurality of possible input means to command an exoskeleton control system. In turn, the exoskeleton control system actuates the position of the motorized braces, resulting in the application of force to, and typically movement of, the body of the exoskeleton wearer. In some cases, the exoskeleton may also be similarly controlled by input from either the wearer of the exoskeleton or a combination of both wearer and physical therapist input to the exoskeleton control system.
Exoskeleton control systems prescribe and control trajectories in the joints of an exoskeleton. These trajectories can be prescribed as position based, force based, or a combination of both methodologies, such as that seen in an impedance controller. Position based control systems can be modified directly through modification of the prescribed positions. Force based control systems can also be modified directly through modification of the prescribed force profiles.
During a rehabilitation session and/or over the course of rehabilitation, it is highly beneficial for the physical therapist to have the ability to modify the prescribed positions and/or the prescribed force profiles depending on the particular physiology or rehabilitation stage of a patient. It is highly complex and difficult to construct an exoskeleton control interface that enables the full range of modification desired by a physical therapist during rehabilitation. In addition, it is important that the control interface not only allow the full range of modifications that may be desired by a physical therapist, but that the interface with the physical therapist be intuitive to the physical therapist, who may not be highly technically oriented. In some situations, it is similarly beneficial for the wearer of the exoskeleton to be made able to modify exoskeleton trajectories.
Exoskeleton control systems receive intent commands from an exoskeleton operator, who may be either a physical therapist or the exoskeleton wearer, and then performs desired actions accordingly. In order to properly execute these actions, a range of sensors are placed throughout the exoskeleton to sense the exoskeleton state. There are a plurality of possible means by which the operator of an exoskeleton, who may be either a physical therapist or the exoskeleton wearer, may input commands into the exoskeleton control system. However, in order to maximize the rehabilitative benefit of the exoskeleton, it would be of great utility to the exoskeleton operator to receive additional information from the exoskeleton control system, which could communicate information on relative force inputs from the exoskeleton and wearer, deflection from prior trajectory cycles, balance of the exoskeleton, guidance or future positioning information, or any of a host of other parameters.
While the prior art includes references to devices intended to indicate safe ranges of motion or desired motions for passive orthoses, these indicators are generally limited to reminding the person of information (typically joint angle) that they already possess. Furthermore, in these cases, the information is provided intermittently when the device determines interference is warranted. The art has not recognized the need for ways that an exoskeleton or powered orthosis needs to communicate its intentions and motion to the person. The examples known in the art of exoskeletons are limited to discrete indicators of state, equivalent to dashboard indicators on a car; this invention is directed at continual feedback that allows the person to understand and be involved in the motion of the device, which is more analogous to the force feedback provided through the steering wheel on modern cars. The driver is able to feel a portion of the force that the car is applying to the steering so that they perceive the forces acting on the car.
There exists an unmet need to provide a device and method that allows for an exoskeleton to communicate information from an exoskeleton control system to an exoskeleton operator, who may either be a physical therapist or exoskeleton wearer, in such a way that the exoskeleton operator is able to intuitively interpret the information communicated by the exoskeleton and utilize this information to improve the rehabilitative benefit or other uses of the exoskeleton.